Possible Causes
WARNING: This page is about a different car, the 2020 Lincoln Navigator. However, it is still accessible from the selected car via links, so may be relevant.
- Wheel speed sensor input concern
- Wheel speed sensor
- AL1: CHECK FOR OTHER ABS MODULE DTCS
- Clear the ABS DTCs.
- Ignition OFF.
- Ignition ON, engine OFF.
Carry out the ABS self-test.
- Are any wheel speed sensor DTCs present which are NOT shown in the DTC Fault Trigger Conditions table?
Yes No DIAGNOSE those DTCs first. REFER to the ABS Module DTC Chart. INSTALL a new wheel speed sensor for the one in question. REFER to the appropriate Removal and Installation procedure in the Anti-Lock Brake System (ABS) and Stability Control article.